When it comes the world outside America, Republican challenger Mitt Romney offers lots of criticisms but few solutions

It is depressing but true that foreign policy rarely has much impact on American elections. This one indisputable area of a president's responsibility affects millions if not billions of people around the world, but to the 200,000 pivotal swing voters in states like Ohio, Colorado and Florida, it is barely an afterthought.

But the world does not stop for presidential elections and explosive events keep intruding on the campaign – from the embassy assault in Libya to increased "Green on Blue" attacks in Afghanistan; and from continuing slaughter in Syria to Iran's quest to achieve a nuclear weapon.

All this international instability offers an opportunity for Mitt Romney to bash President Barack Obama as hell-bent on weakening the United States – "leading from behind" and "apologising" for America (always a conservative crowd-pleaser).

But what would a Romney-Ryan administration actually do differently from President Obama when it comes to foreign affairs? Beyond the sabre rattling, specifics are scarce.

Like Senator Obama four years ago, Governor Romney has little foreign policy experience. At least we knew then that Obama opposed the Iraq war and wanted to ramp up drone strikes against al-Qaeda instead – and now, in regard to killing bin Laden, the phrase "mission accomplished" actually applies.

To date we haven't been told whether Mitt Romney supports the Bush Doctrine of pre-emptive unilateral intervention – a sticky subject even for conservatives these days.

In 2008, candidate Obama tried to compensate for his lack of foreign policy experience by tapping the Senate foreign relations committee chairman, Joe Biden, to be his VP. Romney picked the House budget committee chairman Paul Ryan, a Tea Party policy wonk with no foreign policy expertise.

And so the stage was set for the first and only VP debate this week in Kentucky. Foreign policy occupied much of the questioning and Ryan had a tough time responding beyond campaign rhetoric when it came to specifics.

So while he gamely criticised the Obama administration for not stopping Iran from pursuing a nuclear weapon, he was unable to say what actions a Romney-Ryan administration would take differently. Likewise, Ryan assailed the Syrian slaughter but declined to offer any details about how a new American administration would solve the problem, other than to criticise working with the UN.

Maybe most surreal was Ryan's assertion that Obama's 2014 Afghanistan withdrawal date was evidence of the administration's failure and American decline, but in the next breath asserted that a Romney-Ryan administration would implement the same deadline.

Biden had his share of awkward moments as well, beyond his over-caffeinated impulse to interrupt Ryan. The ongoing congressional hearings on the embassy attack in Libya have shown an administration caught flat-footed at least. Biden bellowed that our ambassador's killers would be brought to justice, but it has been a month and still the murderers run free.

Justice delayed is justice denied.

So much of this political campaign has been a struggle between narrative and facts. One of the few concrete actions Mitt Romney has promised in the area of foreign affairs is to increase America's military spending to four per cent of GDP – which would cost more than $2 trillion extra over the next decade. This hugely expensive, arbitrary benchmark gets predictable cheers from the cheap seats.

But doing the maths is important, especially because the Romney campaign's core is a commitment to rein in the generational theft of deficits and debt.

This $2 trillion dollar sop to the defence industry would overwhelm every specific cut he has proposed to domestic spending and social programmes, while also ensuring ballooning deficits into the future. When asked in the debate how this expense added up against the larger goals of deficit reduction, Ryan essentially had no response.

I called a defence analyst from the libertarian Cato Institute, Benjamin Friedman, looking for some perspective. "To be allegedly sceptical of government spending while being for spending massive amounts on defence it's just sort of the daily hypocrisy or ideological inconsistency," he said.

"If you say you don't think the government can efficiently deliver the mail, it's odd to say it can deliver democracy to Mesopotamia or Afghanistan."

The reality check resonates. With less than a month to the election, and two presidential debates left, this is the time for citizens to demand specifics, to drag arguments out of narrative abstractions and into the realm of actual governing.

But we too often focus on the slogans and the sound-bites and ignore the real-world impact of the plans behind the play-to-the-base politics at home. This is lazy and stupid and something like a civic sin.